Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
Does turning on LED lights in a computer heat up your C inside? Is it better to turn it off? its only 1 blue LED about 10 inches long...does the led make the everything heat up faster or doesn't matter? does it generate HEAT?
Have you tried taking the case temp while it's been off for a while, and then turn it on for bit and seeing if there is any change?
Best way to find out is to test it out.
(The answer to your questions is that it's so close to being "no" it should be there, as in, in comparison to the amount of heat your computer itself is generating, the light is so miniscule that it wouldn't affect anything.)